package com.hudilao.controller;

import com.hudilao.common.R;
import lombok.SneakyThrows;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.annotation.PostConstruct;
import javax.lang.model.element.NestingKind;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

//文件上传与下载
@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {

    @Value("${lao.path}")
    private String basePath;

    @PostConstruct
    public void init() {
        log.info("Base path: {}", basePath);
    }

    //管理端：文件上传
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){
        // 当前file是临时文件，需要转存到指定位置，否则完成之后，文件会消失
        log.info("Received file: {}", file.toString());

        // 检查basePath是否为空
        if (basePath == null || basePath.isEmpty()) {
            log.error("Base path is not configured properly.");
            return R.error("Server configuration error: base path is not set.");
        }

        // 原始文件名
        String originalFilename = file.getOriginalFilename();
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));

        // 使用UUID重新生成文件名，避免重复
        String fileName = UUID.randomUUID().toString() + suffix;

        // 创建目录对象
        File dir = new File(basePath);

        // 判断当前目录是否存在
        if (!dir.exists()) {
            // 目录不存在，创建目录
            dir.mkdirs();
        }

        try {
            // 将临时文件转存到指定位置
            file.transferTo(new File(basePath + fileName));
        } catch (IOException e) {
            log.error("Failed to transfer file", e);
            return R.error("File upload failed.");
        }

        return R.success(fileName);
    }


    //管理端：文件下载
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response)  {

        try {
            //输入流，读取文件内容
            FileInputStream fileInputStream = new FileInputStream(new File(basePath + name));

            //输出流，将文件写回浏览器--展示图片
            ServletOutputStream outputStream = response.getOutputStream();

            response.setContentType("image/jpeg");

            int len = 0;
            byte[] bytes = new byte[1024];
            while((len = fileInputStream.read(bytes))!=-1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }

            //关闭资源
            outputStream.close();
            fileInputStream.close();

        } catch (IOException e) {
            e.printStackTrace();
        }


    }
}
